KR20110033083A - Electrical heating device - Google Patents

Abstract

PURPOSE: The electric heating device interlinks a plurality of heat dissipation elements to the earth potential of the vehicles. In that way the electromagnetic interference which can be caused in the vehicle interior can be eliminated. CONSTITUTION: The housing accepts one generation of heat element(4) and plurality of heat dissipation elements(3) to inside. The generation of heat element has one or more PTC element(20) and electrical strip conductive materials(21, 22). In electrical strip conductive materials, the sides of the PTC element face to face look at and it evens, it locates.

Description

Electric heating device {ELECTRICAL HEATING DEVICE}

The present invention relates to an electric heating apparatus, and more particularly, to an electric heating apparatus for automobiles, in which a plurality of heat dissipating elements structured in at least one heat generating element and a plurality of parallel layers are arranged inside a housing. A plurality of heating elements may be provided inside the housing. In general, two heat dissipation elements are provided for each heating element. In order to dissipate the heat generated by the heat generating element into the medium to be heated, two heat dissipating elements are mounted on opposite sides of the heat generating element. As a result, heat dissipating elements are also used as radiator elements, which are particularly meaningful as heat dissipation elements where thermal loss to the air is intended. The heating elements comprise at least one positive temperature coefficient (PTC) element through which electrical strip conductors are next to each other facing parallel faces.

Class-forming electrical heating devices are used for air conditioning in vehicle passenger compartments, in particular for heating the air, and to compensate for the drawbacks associated with the progressively reduced heat dissipation of modern diesel engines. . These disadvantages include the fact that only insufficient heat is available to heat the vehicle passenger compartment in the initial operating phase of the engine. It is also used to protect the windshield from condensation.

Common electric heating devices are well known, for example EP-A1-1768458. The electrical heating device described in EP-A1-1768458 has an increased electrical insulation strength and is particularly suitable for high voltage operation. In this prior art insulation layers are provided on the outer surface of the strip conductors in each case in order to allow the heat dissipation elements to be placed on the associated heating element with the insulation layer interposed therebetween, and to be dislocation free. Thus, an electrically conductive foreign material located in the electric heating device, for example, a conductive foreign material in contact with the heat dissipating element located on opposite surfaces of the heat dissipating element, does not form a short circuit.

As an electric heating device for achieving the object of this invention, the air heater shown in EP-A1-1768458 can be considered separately, for example a heater for a liquid medium well known in EP-A1-1872986 can be considered. . According to this prior art, the heating elements are enclosed in pockets which are closed downward, and they are in contact with the inner faces of these pockets. In each case the sidewalls of the pockets which extend essentially parallel should be regarded as a heat dissipation element to achieve the object of this invention. It is not of interest that each of the heat dissipation elements is provided as a separate element. Rather, the representation according to claim 1 is based on the fact that the heat dissipation elements are in each case provided in parallel planes which are located opposite each other of the heat generating element.

The first object of the invention is to provide an electric heating device of the type mentioned in the introduction. This may, in particular, meet practical needs in an improved manner with high voltage operation.

A second object of the present invention is to provide the possibility of screening due to the heat dissipation element connected to the ground potential, and by connecting a plurality of heat dissipation elements to the ground potential of the vehicle which may cause electromagnetic interference which may be caused inside the vehicle. This is to reduce unwanted effects.

A third object of the present invention is to prevent a short circuit between the heating elements by the heat dissipation elements even when there are defects in the insulating layer.

The object of the invention can be achieved as an electric heating device having the features of claim 1 according to the invention. This differs from the prior art in which at least one heat dissipation element forms the general class mentioned above in that it can be in contact with the associated heat dissipation element with an intervening electrical insulation layer interposed therebetween and electrically connected to the ground potential of the vehicle. .

The heat dissipation element in the electric heating apparatus according to the invention is already known in EP-A1-1768458 or EP-A1-1872986, in order to receive heat generated by the heat-generating element from the beginning through thermal diffusion and from the heat dissipation element. In order to dissipate the heat to the flow of the medium through the electrical insulation layer is in contact with the heating element specified in the heat dissipation element in the middle. Such a heat dissipation element is provided potential-free to the heating element because of the insulating layer and can also be electrically connected to the ground potential of the vehicle. Such a connection can generally be generated by electrical contact with a corresponding heat dissipation element having an electrical conductor arrangement inside the electrical heating device, where the electrical heating device can be connected to the ground of the vehicle via the electrical interface formed therein. .

The electric heating device according to the invention offers the possibility of screening due to the heat radiation element connected to ground potential. Therefore, it is possible to arrange the heat dissipation elements connected with the ground potential to the outside of the heating block, for example to screen the heating block from the outside. In general, the layer structure of at least one heating element and adjacent heat dissipation elements can be thought of as a heating block. Depending on the generated heating power, multiple parallel layers of heating elements can form the heating block. In order to practice the invention the heating block is preferably suspended in the housing under tension of a spring arranged inside the housing. In general, the housing is a housing that surrounds the heating block like a frame.

Moreover, the present invention provides the advantage that a heat dissipation element consisting of a meander-type, which is generally a bundle of bent metal sheets, can extend beyond the heating block. Therefore, it is conceivable that the metal sheet material of the heat dissipation element extends straight and parallel over the layers of the layer structure to provide screening of the heating block through the heat dissipation element on the extension of the layers of the layer structure and on the side adjacent to the heating block. Can be. Here, the control elements of the regulating device arranged in the structural unit unit with the electric heating device can be provided. And control elements can be included in the screen by this type of extension of the metal sheet material of the heat dissipation element.

The screen of the heating block or the screen of the necessary control elements is less important when it comes to Excessive Field Strength (EMC) issues. In electrical heating devices of the general type of a vehicle, high power is usually switched which can cause electromagnetic interference inside the vehicle. By connecting one or preferably all of the heat dissipation elements of the heating block to the ground potential of the vehicle, this unwanted effect can be reduced or even eliminated.

According to a preferred embodiment of the invention, the housing is provided with an exposed electrical connection element and at least one ground which supplies current to the electrical strip conductors. These connecting elements are simply developed in the form of plug elements for allowing the electrical heating device to be electrically connected to the vehicle's electrical system and the vehicle's ground after completing the assembly.

With regard to the aforementioned EMC problems, it has been proven that it is advantageous if the ground connection is provided in an annular form around at least one electrical connection element, and the ground connection is connected to the screen of the connection cable leading to the electrical connection element. The electrical connection cable may be a power cable. That is, it may be a power cable for power supply for the operation of the electric heating device. All electrical supply lines are provided with connecting cables. The electrical connection cable may be a signal cable for the drive circuit elements of the regulating device which, wherever applied, serves as an integral part of the electrical heating device. Regardless of the number of cable cores, electrical connection cables are generally provided with a screen connected to ground and can be connected to an annular ground connection. Typically the connection takes place via a plug connection.

Use under the high voltage of a typical electric heating device, ie operation at a voltage of 220 V and above, is common for insulation reasons to keep all surfaces of the electric heating device in the flow of medium without potential for safety reasons. To each heating element at the outer surface of the electrical strip conductor. However, since damage to the insulating layer cannot always be ruled out over the service life of the electric heating device, according to a more preferred embodiment of the invention, a ground monitor is assigned to at least one heat dissipating element that can be connected to a ground potential. It is suggested to be. Such a ground monitor monitors the potential of the corresponding heat dissipation element and generally compares the potential of the heat dissipation element with the ground potential of the vehicle. A faulty insulation layer immediately leads to a potential difference, which can be detected by the ground monitor and informed in the form of a reminder signal.

Due to the proposed feature of the invention, the electric heating device according to the invention is particularly suitable for the operation of a high performance electric vehicle. Here, the electric heating device according to the present invention can be operated even at an operating voltage equivalent to 500 V in an electric vehicle or a hybrid vehicle. The measuring methods in the above mentioned cases, individually or in combination, provide safety for the electric heating device and facilitate the operation of the electric heating device according to the invention at a moderately high voltage. Thus, according to the present invention, which is an electric heating device, an output of heat far beyond the current general range of about 2 kW can be provided. Also conceivable is an electric heating device having a heat output between 3 kW and 10 kW, in particular equivalent to 6 kW. Screening of the heating block by heat dissipation layers connected to ground not only results in improved electrical preheaters with respect to EMC problems, but all heat dissipation elements, ie all heat dissipation elements can be connected to the ground connection and monitored by a ground monitor. Can be.

Nowadays, in high voltage operation of the electric heating device, insulating layers may be provided between all the heat dissipating elements and the heat generating elements. These insulating layers may be formed of a ceramic or plastic film or a combination of the two materials. The insulating layer can exhibit high electrical dielectric strength. Due to the good thermal conductivity, it is very probable to use ceramic layers as an electrical insulator between the heating element and the adjacent heat dissipating element. However, ceramic materials have the disadvantage of being very brittle. As generally accepted, this disadvantage can be overcome through a sandwich structure between the ceramic material and the less brittle material, for example a plastic film. Nevertheless, in applying a high voltage, the occurrence of a short circuit must be prevented. Here, however, based on the error signal sensed by the ground monitor and the ground monitor, the power supply current can be switched off by the regulating device assigned to the ground monitor.

In the present invention, however, the following measurements are also proposed for how electrical safety can be improved, in particular for how safety can be improved during operation at high voltages.

Electrical safety and leaky currents flowing through or optionally passing through a provided electrical insulator cannot be excluded, and in accordance with a preferred embodiment of the invention all heating elements are in each case adjacent heat generation. If the elements are installed in the housing in such a way that they are located in strip conductors of the same polarity located opposite each other, no serious problems arise. Although the provided heating elements between the heat dissipating elements located opposite each other and the insulating layer in the case of the insulating layer, the provided heating elements between the heat dissipating elements and the heating elements are electrically insulated from the heat dissipating elements, The heat dissipation element provided between them is positioned against each of the strip conductors of the same polarity with the insulating layer interposed therebetween. Thus, one embodiment is manufactured such that the heat dissipation element is positioned internally between the first set of heating elements and is electrically insulated by an insulating layer between the two anode strip conductors. On the other hand, the next heat dissipation element is provided between two cathodes with an insulating layer interposed therebetween. Instead of one heat dissipation element, a plurality of heat dissipation elements which are preferably identically formed may be provided between the two heat dissipation elements. Even if there are defects in the insulating layer, therefore, a short circuit between the two heating elements is not represented by the heat dissipation elements.

The electrical safety of one embodiment having this property can be a further improvement in that the fault current measuring means are provided as part of the regulating device of the electric heating device. Such fault current measuring means can determine, for example, leakage currents or creep currents and find faults in the electrical insulation required. The signal informing the fault from the fault current measuring means results in the completed electrical heating device being switched off. Fault current measuring means can also be used before the electric heating device is transported to detect any possible combination of faults.

It is essential to the invention that the above-described embodiment, i.e., strip conductors of adjacent heating elements, in each case are positioned opposite to each other with the same polarity. It is not necessary for the heat dissipation element to be electrically connected to ground potential to realize this solution. In each case, however, it is desirable to provide an insulating layer between the heat dissipation element and the designated heat dissipation element. The proposed solution is particularly important if more than two heating elements are installed inside the housing.

In connection with a simple combination, the fault current measuring means and / or the ground monitor are preferably essentially housed in the housing and in fact as part of an adjustment device arranged in the housing. In this embodiment, the electric heating device can be installed in a standard configuration inside the vehicle. Normally, the regulating device can be installed in a data communication network via the bus system of the vehicle. Such a communication network can handle fault signals received from the ground monitor and can be notified via a service connector or via a display in the vehicle passenger compartment.

Claims 7 and 9 provide a further improved state of the screen which has already appeared. Therefore, preferably the heat dissipation elements outside the heating block are electrically interconnected to form a screen surrounding the heating device. External heat dissipation elements may be connected on one or both sides such that the heating block and the optional adjustment device are essentially housed inside the housing and circumferentially surrounded by the screen. The screen is normally circumferentially extending between the inlet and outlet through which the medium is heated, surrounding the heating block and the designated regulator. The screen, however, has walls extending parallel to the plane through which the medium passes at the inlet and / or outlet of the housing to heat the medium.

For easy deformation of the screen portion the screen panel preferably extends laterally with respect to the layers of the heating block and at the same time is electrically connected with external heat dissipation elements. In relation to the heating block the screen panel is arranged to surround at least one heating element from the outside. The electrical connection here between the external heat dissipation elements and the screen panel is generated using a plug connection. The heat dissipation elements and the at least one screen panel are preferably formed by stamping and / or bending of the metal thin strips.

According to one embodiment of the present invention as described above, there is an effect of meeting the practical need in an improved manner by high voltage operation.

It also offers the possibility of screening due to the heat dissipation element connected to ground potential.

And, by connecting a plurality of heat dissipating elements to the ground potential of the vehicle, electromagnetic interference, which is usually caused by switching at high power inside the vehicle, can reduce or even eliminate this unwanted effect.

In addition, there is an effect that a short circuit does not occur between the heat generating elements by the heat dissipation elements even in the case of defects in the insulating layer.

The invention can be further embodied by the following description in accordance with one embodiment associated with the drawings. The drawings are as follows.
1 is a side view of an embodiment of the present invention;
FIG. 2 is a side perspective view of an opposite parallel surface of the embodiment shown in FIG. 1;
FIG. 3 is an enlarged detailed view of part III shown in FIG. 2;
4 is a perspective view showing the housing portion shown in FIG. 2 before installation of the heating block;
5 is an enlarged detailed view of part V shown in FIG. 4;
Figure 6 is a side view showing the side of a heating block of one embodiment in order to clearly show the electrical connection of the individual elements of the heating block for the purposes of the present invention.

1 shows a side view of an embodiment of an electric heating device with a housing 1 in the form of a frame. Here, the housing 1 is formed of two plastic shells and houses the heating block 2. The heating block 2 comprises a plurality of heating elements 4 provided in layers parallel to the plurality of heat dissipating elements 3. According to this embodiment shown, at least one longitudinal member of the frame-shaped housing 1 is provided with a spring tension that allows the layers of the layered structure to be pressurized to each other. A spring element (not shown) is provided to secure the heating block 2. On the side of the heating block 2 the housing 1 has a flange 5 and a control housing 6 protruding beyond the mounted flange 5. In this control housing 6 there is an electric control device, which is not shown anymore.

This embodiment shown in FIG. 1 may be electrically connected to the vehicle's electrical system and may also be connected to the vehicle's data network by means of an adjustment cable or a power cable. In the illustrated embodiment, the plug connection identified by reference numeral 7 is provided in the control housing 6 for the power cable and ground connection. The plug connection is made of plastic attachments and guide surfaces, although no longer specifically shown. The power cable has a circumferentially shaped screen, which is electrically connected to the annular ground connection 8 when a plug connection is provided. This annular ground connection 8 protrudes beyond the control housing 6 and surrounds the electrical connection elements 9a-9c for the electrical connection of the power cable. The ground connection 8 is connected with the individual heat dissipation elements 3 using conductor tracks formed inside the housing 1. The electrical connection elements 9a-9c are connected with the individual heating element 4 or the grouped heating element 4 via power switches housed inside the control housing 6 which supplies current.

The side perspective view according to FIG. 2 shows the structure of the housing 1 more clearly. The housing 1 consists of two housing elements 1a, 1b. Each of the housing elements 1a, 1b is identically formed, at which end the control housing 6 protrudes. In the control housing 6 there is provided a regulating device for the electric heating device, which in particular comprises electronic regulating arrangements for the regulation of the heating block 2. The heat dissipated by the electronic conditioning arrangements exits the air flowing through the heating block 2 via cooling elements, which can be identified with reference 30. In this respect, on the side close to the opening of the heating block, the housing 1 forms each of three flow channels leading to the cooling element 30. The transverse member 11 of the housing provided adjacent to the cooling element 30 is provided with metal claws 12 and mounted inward next to the conductor element 10. Here, the metal claws 12 are located similar to the height of the inner surface of the housing element 1a and the metal thin strips of the heat dissipation element 3 are in electrical contact with the bent meandering element 3. Interact with All heat dissipation elements 3 interact with corresponding metal claws 12, ie all heat dissipation elements 3 are electrically interconnected via conductor elements 10.

As can be seen in particular from FIG. 4, the metal claws 12 are formed by stamping into sheet metal bands. As seen from FIG. 3 and as can be seen from FIG. 5, the metal claws 12 are free from the heating block side of the longitudinal side of the metal sheet bundle by stamping, and a tooth row for performing stamping and bending at the side. Formed through 13. This tooth row 13 has a ridge extending in the flow direction, ie perpendicular to the layers of the heating block 2 on which the tooth contour protrudes. This ridge interacts with the corrugated ribs of the heat dissipation element 3. A hole 14 is provided in the center of the metal claw 12 to minimize the resistance of the flow generated by the metal claw 12.

The metal claws 12 protrude from the longitudinal conductor element base 15, which is configured to extend side by side adjacent to the interior of the transverse member 11. For mounting, latching receptacles 16 that can be latched are cut onto the transverse member 11. These latching receptacles 16 that can be positioned are located between the cooling elements 30 (shown in FIG. 2) in each case. The spring-loaded catches 17 are formed on the conductor element base 15 by stamping and bending. Thus, the conductor element base 15 may be mounted to the housing 1 by interaction with the catchable receptacles 16 with clipping and catching protrusions 17. The conductor element base 15 is normally electrically connected to the parts of the control housing via contact of the ridge, which may be formed, for example, by stamping and / or bending. Normally located here is a ground monitor and / or fault current measurement means electrically connected to the conductor element base 15.

The heating block 2 is inserted into the unit as can be seen in FIG. 4, which is formed of an injection molded plastic part 1a, a metal sheet and has a conductive element base 15 and a claw 12. It is formed of a conductive element 10 including. In each case the heat dissipation element 3 is here attached with a claw 12, respectively. Moreover, at least one spring is inserted in the housing portion 1a, the spring subjecting the heating block and each spring under tension to the layers forming the heating block, which is after the final assembly of the electric heating device. In fact it is the force that the spring exerts across the layers of the heating block 2 in the plane of the heating block 2.

The elements of the heating block 2 and at least one spring element are mounted to the housing part 1a, and the housing part 1a is sealed. In the closure of the housing, defined by reference numeral 18, latching tongues provided on the housing portions 1a, 1b spring into the spring to enable the housing portions 1a, 1b to engage. place). At the end of the joining process in the direction of the air flow through the heating block 2, the claws 12 with teeth 13 are forced by the heat dissipating element, which subsequently and partially undergo plastic deformation. Will receive. At the end of the joining process, the claw 12 is electrically stable with the heat dissipation element 3.

The electrical arrangement of the individual elements of the heating block 2 on the connecting elements 8, 9 can be determined as illustrated in FIG. 6.

A plurality of PTC elements 20 each provided in parallel and aligned relative to each other, each of which comprises at least one PTC element 20 arranged between the strip conductors 21 and 22 and supplied with current through the strip conductors 21 and 22 The heating block with heating element 4 is shown schematically. On the outer surface of the strip conductors 21, 22 are electrically insulating layers 23, respectively.

The heat dissipation elements 3 are formed of curved ribs and are respectively adjacent to both sides of the heat generating element 4. As can be seen in FIG. 6, the two heating elements 4.1, 4.2; 4.5, 4.6 are divided into a heat dissipation element 3.2 and a heat dissipation element 3.8, respectively. Easily, two identical heat dissipating elements 3.3, 3.4 are provided between two neighboring heat generating elements 4.2, 4.3.

Specifically, in FIG. 6, all of the heat generating elements 4 each have an insulating layer 23 on the outer surface thereof so as to provide potential free to all the heat dissipating elements 3. Is formed of the claw 12 and is electrically connected to a ground connection 8 through ground connections, which are defined by reference numeral M in the electrical connection diagram according to FIG. 6, respectively. The corresponding situation applies to strip conductors 21, 22 formed of thin film metal bands in connection with the electrical connection elements 9a-9c for power. The strip conductors 21 are respectively connected to the negative electrode or the ground terminal, respectively, and the strip conductors 22 are respectively electrically connected to the positive electrode of the power source. However, this connection sometimes occurs through intermediate switching of the power switches contained in the control housing 6 and can be switched via logic circuitry within the control housing. Furthermore, a ground monitor (not shown) is provided in the housing, all ground connections M are electrically connected, and preferably ground connection with them in order to determine any possible defects in the insulator 23 causing a potential difference. The potential balance between (8) can be recognized. However, the alignment is selected as shown in FIG. 2 so that a short circuit does not occur even when a defect in the insulator occurs. The same polarities of the different and adjacent heating elements 4 are therefore located opposite each other in each case. The thin-film metal bands of the same polarity are thus located on both sides of the heat dissipation elements 3.2, 3.3, 3.4, 3.5, 3.6, 3.7 or 3.8 aligned with the two heating elements 4 and separated from the insulator.

In FIG. 6 a defined embodiment of the screen of the heating block 2 is shown schematically. The screen of the heating block 2 is formed by a screen panel 24 extending essentially at right angles from the layers of the heating block 2 and connected to the end of the outer heat dissipating element 3.1 or 3.9. Suitably the screen panel 24 may be provided such that the control elements of the adjusting device are located in the screen. The screen can also be formed by way of example as part of a housing cover for the control housing 6, which is electrically connected with the external heat dissipating elements 3.1 or 3.9 only after sealing of the control housing 6 by the housing cover. Can be connected.

1: housing
1a, 1b: housing element
2: heating block
3: heat dissipation element
4: heating element
5: mounting flange
6: control housing
7: plug connection
8: ground connection
9a to 9c: connecting element
10: conductor element
11: transverse member
12: claw
13: tooth row
14: hall
15: conductor element base
16: receptacle that can jam
17: Hanging projection
18: latching pin
20: PTC element
21: strip conductor
22: strip conductor
23: insulation layer
24: screen panel
25: cooling element
M: ground connection
-: Cathode of power current
+: Anode of power current

Claims (10)

In the vehicle electric heating device,
At least one having a housing, and inside the housing, at least one PTC element 20 and electrical strip conductors 21, 22 with the surfaces of the at least one PTC element 20 facing each other side by side; And a plurality of heat dissipating elements 3 arranged in parallel layers fixed to mutually adjacent sides of the heating element 4 and the at least one heating element 4,
At least one heat dissipation element 3 is located in the middle of the electrically insulating layers 23 in the designated heating element 4,
Externally exposed electrical connection elements 9a-9c and the at least one heat dissipation element 3 for supplying current to the electrical strip conductors 21, 22 can be electrically connected to the ground potential of the vehicle. Electrical heating device characterized by a ground connection (8).
The method of claim 1,
The ground connection 8 is provided annularly at least around the at least one of the electrical connection elements 9a-9c and can be connected to the screen of the connection cable which is connected to the electrical connection elements 9a-9c. Electric heating device.
3. The method according to claim 1 or 2,
All heat dissipating elements (3) are characterized in that they are located in the middle of the electrical insulation layer (23) in the designated heating element (4) and can be connected to the ground potential of the vehicle.
The method of claim 1,
Electrical heating device, characterized in that at least one grounding monitor is assigned to at least one heat dissipation element (3).
The method of claim 4, wherein
A control device arranged in said housing,
And said regulating device comprises said ground monitor.
The method of claim 1,
The external heat dissipating elements (3.1, 3.9) are electrically interconnected to form a screen that electrically surrounds the electric heating device.
The method of claim 6,
And said screen circumferentially surrounds said electric heating device.
The method of claim 1,
All heating elements (4) are installed inside the housing such that each of the adjacent heating elements (4) is positioned with the strip conductors (21, 22) of the same polarity facing each other.
The method of claim 1,
The external heat dissipating elements 3. 1, 3.9 can be electrically interconnected by a screen panel 24 extending transverse to the layers and enclosing at least one heating element 4 externally. Heating device.
The method of claim 9,
An electrically conductive screen connected to said screen panel (24) and screening a controller of said electric heating device.

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